[LIT][SYCL] Reduce compilation time for known_identity test (#7498)

Signed-off-by: Tikhomirova, Kseniya <[email protected]>

Author: KseniyaTikhomirova

sycl/test/basic_tests/known_identity.cpp

@@ -1,4 +1,4 @@
-// RUN: %clangxx -fsycl -Xclang -verify %s -Xclang -verify-ignore-unexpected=note,warning -o %t.out -std=c++17
+// RUN: %clangxx %fsycl-host-only -Xclang -verify %s -Xclang -verify-ignore-unexpected=note,warning -o %t.out -std=c++17 %sycl_lib -L%sycl_libs_dir
 // RUN: %t.out
 // expected-no-diagnostics
 

sycl/test/lit.cfg.py

@@ -87,6 +87,7 @@
 config.substitutions.append( ('%llvm_build_bin_dir',  config.llvm_build_bin_dir ) )
 
 config.substitutions.append( ('%fsycl-host-only', '-std=c++17 -Xclang -fsycl-is-host -isystem %s -isystem %s -isystem %s' % (config.sycl_include, config.opencl_include_dir, config.sycl_include + '/sycl/') ) )
+config.substitutions.append( ('%sycl_lib', ' -lsycl6' if platform.system() == "Windows" else '-lsycl') )
 
 llvm_config.add_tool_substitutions(['llvm-spirv'], [config.sycl_tools_dir])